Risk factors for HIV-associated neurocognitive disorders (HAND) in sub-Saharan Africa: the case of Yaoundé-Cameroon

Prevalence and variability of HIV/AIDS-associated neurocognitive impairments in Africa: a systematic review and meta-analysis

BACKGROUND

HIV/AIDS-associated neurocognitive impairments negatively affect treatment adherence, viral load suppression, CD4 count, functionality, and the overall quality of life of people with seropositive status. However, huge variability is observed across primary studies regarding the prevalence and determinants of neurocognitive impairment in people with HIV/AIDS. This systematic review and meta-analysis sought to determine the pooled prevalence of neurocognitive impairment and identify factors contributing to variations in its estimate among people living with HIV/AIDS in Africa.

METHODS

A comprehensive literature search of scientific databases (Medline/PubMed, SCOPUS, Web of Science, PsycINFO, and EMBASE) was performed from inception onward. Google and Google Scholar were also searched for grey literature. Research articles available until July 15, 2022 were included. We used STATA-version 14 statistical software for analysis. A random effect model was executed to pool the reported prevalence of neurocognitive impairments. Subgroup analysis was done to show variations in the prevalence of neurocognitive impairments and factors that might contribute to these variations.

RESULTS

A literature search resulted in 8,047 articles. After the removal of duplications and thorough evaluation, a total of 49 studies were included in the meta-analysis. The prevalence of HIV/AIDS-associated neurocognitive impairments was highly variable across studies, ranging from 14% to 88%, yielding the pooled prevalence of HIV/AIDS-associated neurocognitive impairment to be 46.34% [95% CI (40.32, 52.36)] and I² = 98.5% with a P-value of 0.001.

CONCLUSIONS

A large proportion of people living with HIV/AIDS in Africa have HIV/AIDS-associated neurocognitive impairment. This illustrates the need to establish practical approaches to early identification and effective control of HIV/AIDS-associated neurocognitive impairments. However, there were variabilities in the reported prevalence of HIV/AIDS-associated neurocognitive impairments across studies. This further demonstrates the need to have consistent measurement approaches.

TRIAL REGISTRATION

PROSPERO 2022, "CRD42020166572".

HIV-Associated Dementia: Associated Factors and Characteristics of Cognitive Domain Abnormalities in Elderly People Living with HIV Treated with Highly Active Antiretroviral Therapy

This study aimed to evaluate the prevalence and associated factors of HIV-associated dementia (HAD) in people living with HIV (PLWH) aged ≥ 60 years who are currently treated with highly active antiretroviral therapy. A cross-sectional study was conducted on adult (age ≥ 60 years) PLWH at the infectious clinic, Vajira Hospital, Navamindradhiraj University, Thailand, between August 2019 and March 2021. We collected the patients' characteristics and performed Montreal Cognitive Assessment and Instrumental Activities of Daily Living test to determine whether they have HIV-associated neurocognitive disorders (HAND), which we further classified into asymptomatic neurocognitive impairment (ANI), mild neurocognitive disorder (MND), and HAD. Finally, we evaluated the prevalence, associated factors, and characteristics of cognitive domain abnormalities in these patients. We enrolled 84 elderly PLWH patients consisting of 43 (51.2%) males. The mean patient age was 63 years (SD ± 3.9), and the median duration of HIV infection was 13 (SD ± 5.7) years. All the patients had undetectable HIV viral load. Among them, seven (8.3%) had no neurocognitive impairment, 61 (72.6%) had ANI, three (3.6%) had MND, and 13 (15.5%) had HAD. After confounder adjustment, the patient age of ≥ 65 years was found to be significantly associated with dementia (odds ratio = 5.97, 95% CI: 1.51-23.57). Significant difference in the mean score of all cognitive domains was observed between the patients with HAD and those with normal cognitive status. HAND is common in PLWH. Age older than ≥ 65 years is a risk factor of HAD.

Dementia in Africa: Current evidence, knowledge gaps, and future directions

In tandem with the ever-increasing aging population in low and middle-income countries, the burden of dementia is rising on the African continent. Dementia prevalence varies from 2.3% to 20.0% and incidence rates are 13.3 per 1000 person-years with increasing mortality in parts of rapidly transforming Africa. Differences in nutrition, cardiovascular factors, comorbidities, infections, mortality, and detection likely contribute to lower incidence. Alzheimer's disease, vascular dementia, and human immunodeficiency virus/acquired immunodeficiency syndrome-associated neurocognitive disorders are the most common dementia subtypes. Comprehensive longitudinal studies with robust methodology and regional coverage would provide more reliable information. The apolipoprotein E (APOE) ε4 allele is most studied but has shown differential effects within African ancestry compared to Caucasian. More candidate gene and genome-wide association studies are needed to relate to dementia phenotypes. Validated culture-sensitive cognitive tools not influenced by education and language differences are critically needed for implementation across multidisciplinary groupings such as the proposed African Dementia Consortium.

A Cross-Sectional Study of Human Immunodeficiency Virus-Associated Neurocognitive Deficit in Central India

Background

With the advent of modern era of combination antiretroviral therapy (cART) and increased longevity of people living with human immunodeficiency virus (PLHIV), human immunodeficiency virus-associated neurocognitive disorder (HAND) is commonly observed. This study explores the prevalence of HAND and the demographic and treatment variables in people with HAND, in Central India.

Research methodology

PLHIV on cART visiting HIV clinic underwent screening for substance abuse using CAGE-AID, and depression using PHQ-2 followed by PHQ-9. The screening rules out overt conditions which might interfere with cognitive abilities of the individual and thereby act as confounding factor. Thus, a sample population of 96 was obtained, on whom International HIV Dementia Scale (IHDS) was applied to screen for dementia. Out of 96, 16 individuals detected to suffer from HAND. Quality of Life was assessed by Patient’s Assessment of Own Functioning Inventory (PAOFI).

Results

Prevalence of HAND was estimated to be 16/96 (16.66%). It was more common amongst unmarried individuals (p < 0.001) and lower educational status (p < 0.01) among social variables; while shorter duration of ART (<3 years) (p < 0.01) and lower CD4 nadir (≤200 cell/mm³; p<0.01) showed significant correlation among clinical variables. PAOFI revealed significant association between HAND and quality of life (p-value < 0.01, CI = 95%). Modified Mental State Examination (3MS), which determines cognitive ability in various domains based on tasks, was mostly affected for - similarities and read and obey (for 43.75% population).

Conclusion

Social and clinical variables play a significant role in development of HAND. Routine screening for HAND in PLHIV will help in early identification and management of the disease. The quality of life for those suffering from the burden of HIV and HAND can be significantly improved if approached and treated early in the course of the disease.

A Meta-Analytic Review of the Effect of Antiretroviral Therapy on Neurocognitive Outcomes in Adults Living with HIV-1 in Low-and Middle-Income Countries

HIV-associated neurocognitive impairment remains a challenge even in the era of antiretroviral therapy (ART). Over 90% of people living with HIV are in low- and middle-income countries. Hence, it is not surprising that such countries bear a considerable burden of comorbidities like HIV-associated neurocognitive impairment despite an overall increase in life expectancy. The literature suggests differences in patient characteristics, clinical profile, prevalent HIV subtypes, treatment choices, pharmacogenetics, and socioeconomic factors between low- and middle-income countries compared with high-income countries. Therefore, we aimed to evaluate the effect of ART on neurocognitive outcomes in low- and middle-income countries. A comprehensive search of five databases (PubMed, CINAHL, CENTRAL, PsychInfo, Google scholar) for studies published between 1996 to 2020 was performed to identify studies that reported neurocognitive outcomes in ART-treated and ART naïve HIV positive individuals. Two independent reviewers conducted study screening, data extraction, and evaluation of the risk of bias. Pooled effect size estimates (Hedges' g) and 95% CI were computed using random-effects models. Sensitivity analysis, subgroup analysis, meta-regression, and evaluation of publication bias were also conducted. Forty studies (24 cross-sectional, 13 longitudinal studies, and two randomized controlled trials) contributed to a series of meta-analyses. We found significant small to moderate effects of antiretroviral therapy for global cognition (Hedges' g observed = 0.30; 95% CI: 0.15, 0.44; k = 25; p = 0.0003; I² = 92.1%; tau = 0.32; Q = 305.1), executive function (Hedges' g = 0.24, 95%CI: 0.02,0.46; p-0.04; k = 8; I² = 37.5%; tau = 0.23; Q = 11.2), and speed of information processing (Hedges' g = 0.25, 95% CI: 0.05, 0.45; k = 9; p = 0.02; I² = 86.4%; tau = 0.21; Q = 58.9). We found no significant ART effect on attention-working memory, learning and memory, motor function, and verbal fluency. No significant effect was seen with the duration of therapy, efavirenz use, and Central Penetrating Effectiveness (CPE) of antiretroviral therapy. Subgroup analyses identified study design (between-group and within-group; cross-sectional and longitudinal) and normative scores as significant sources of heterogeneity. Meta-regression analysis indicated that nadir CD4 modified the magnitude of ART's effect on cognitive outcomes. Age, gender, and country income-group were not significant moderators. Our findings provide systematic evidence that antiretroviral therapy improves neurocognitive outcomes in the domains of global cognition, executive function and speed of information processing, of people living with HIV in low- and middle-income countries, especially those with advanced immunosuppression. However, these findings are not definitive as they are limited by the probability of publication bias, high heterogeneity, and exclusion of significant confounders. Prospero registration number: CRD42020203791.

Meta-analysis of factors affecting prevalence estimates of HIV-associated neurocognitive disorder in sub-Saharan Africa

Successful treatment of HIV with anti-retroviral therapy (ART) is resulting in more people living with HIV-associated neurocognitive disorder (HAND). In sub-Saharan Africa, this calls for strategic planning and judicious allocation of scarce resources, which requires an accurate estimate of the prevalence of HAND. Estimates of the prevalence of HAND in sub-Saharan Africa vary greatly, between 18.8% and 88.3%. This variability may be explained by factors such as different diagnostic approach, neuromedical examination, ART status, sampling method, substance abuse, assessors’ qualification, depression and outcome measure. Different methods of diagnosing HAND, different outcome measures and non-random sampling techniques make it almost impossible to accurately estimate the prevalence of HAND in sub- Saharan Africa, often resulting in overestimation of the burden of disease. Consumers of health research should consider certain study characteristics and exercise appropriate caution when interpreting burden of disease in sub-Saharan Africa, especially when pursuing policy shift. Underestimating the prevalence of HAND will certainly affect the capacity and speed of containment, while overestimating will draw unnecessary attention and result in the misallocation of scarce resources.

MRI imaging features of HIV-related central nervous system diseases: diagnosis by pattern recognition in daily practice

With the advent of antiretroviral therapy (ART), the prognosis of people infected with human immunodeficiency virus (HIV) has improved, and the frequency of HIV-related central nervous system (CNS) diseases has decreased. Nevertheless, mortality from HIV-related CNS diseases, including those associated with ART (e.g., immune reconstitution inflammatory syndrome) remains significant. Magnetic resonance imaging (MRI) can improve the outlook for people with HIV through early diagnosis and prompt treatment. For example, HIV encephalopathy shows a diffuse bilateral pattern, whereas progressive multifocal leukoencephalopathy, HIV-related primary CNS lymphoma, and CNS toxoplasmosis show focal patterns on MRI. Among the other diseases caused by opportunistic infections, CNS cryptococcosis and CNS tuberculosis have extremely poor prognoses unless diagnosed early. Immune reconstitution inflammatory syndrome shows distinct MRI findings from the offending opportunistic infections. Although distinguishing between HIV-related CNS diseases based on imaging alone is difficult, in this review, we discuss how pattern recognition approaches can contribute to their early differentiation.

Neurocognitive Effects of Antiretroviral Initiation Among People Living With HIV in Rural Uganda

BACKGROUND

HIV-associated neurocognitive disorders remain prevalent despite effective antiretroviral therapy (ART), but there are limited longitudinal data on people living with HIV (PLWH) in sub-Saharan Africa. We examined neuropsychological (NP) performance in PLWH in a longitudinal study in Uganda.

METHODS

Participants enrolled through the Rakai Community Cohort Study (400 ART-naive PLWH and 400 matched HIV-negative persons) were administered NP assessments. In 2017, PLWH who had initiated ART underwent a 2-year follow-up assessment. Demographically adjusted Z-scores for each NP test were established using data from the HIV- controls. Multivariable linear and logistic regressions were conducted to examine group differences in NP performance. Mixed-effects regressions were conducted to examine ART-related changes in NP outcomes.

RESULTS

Of 333 PLWH who returned for their 2-year follow-up visit, 312 (94%) had initiated ART. Those on ART had a mean age of 35.6 years (SD ± 8.5 years) and mean education of 5.4 years (SD ± 3.3 years); 49% were women. ART-associated NP improvements occurred in verbal learning and memory (P's < 0.05), motor (P's < 0.01), and some measures of processing speed (P = 0.002), whereas there were declines in attention/working memory (P's < 0.001) and semantic fluency (P < 0.001). Pre-ART CD4 count and efavirenz use were associated with a more impaired change in NP performance.

CONCLUSIONS

PLWH in this resource-limited setting showed improved neurocognitive performance on most NP tests after ART initiation. However, the declines in attention/working memory and fluency performance, as well as relationship to efavirenz, warrant further study.

HIV-associated neurocognitive impairment in stable people living with HIV on ART in rural Tanzania

OBJECTIVES

Few studies have assessed cognitive impairment among healthy people living with HIV (PLWH) who are stable on antiretroviral treatment (ART) in sub-Saharan Africa.

METHODS

We conducted a cross-sectional study among a random sample of stable adult PLWH from rural Tanzania on ART for more than 1 year and without immunological failure or pre-existing neurological disease. We evaluated the prevalence and risk factors for neurocognitive impairment (NCI), assessed through neuropsychological tests, functional and depression questionnaires and defined as a mean Z-score ≤ -1 in two or more cognitive domains.

RESULTS

Among 243 participants [median age = 44.3 years (interquartile range: 36-52] and 71% female] we found a rate of NCI of 19.3% (95% confidence interval: 14.8-24.8%). Memory and psychomotor domains demonstrated the highest impairment. Independent predictors of NCI were age and self-reported alcohol use. Other classical risk factors were not associated with HIV-associated NCI.

CONCLUSION

Despite effective ART roll-out, NCI remained a prevalent condition in this healthy rural Tanzanian population of PLWH on ART. Age and alcohol use were key risk factors.

Effects of HIV infection, antiretroviral therapy, and immune status on the speed of information processing and complex motor functions in adult Cameroonians

HIV-associated neurocognitive deficits include impaired speed-of-information processing (SIP) and motor functions. There is lack of Cameroonian adult norms for assessing SIP or motor functions. This study of 683 Cameroonians (320 HIV+, 363 HIV-) establishes demographically-adjusted norms for six SIP [Wechsler-Adult-Intelligence-Scale (WAIS)-III Digit Symbol (WAIS-IIIDS) and Symbol Search (WAIS-IIISS), Stroop Color-Naming, Stroop Word-Reading, Trail-Making Test-A (TMT-A), Color Trails-1 (CTT1)], and two motor function [Grooved Pegboard-dominant (GP-DH) and non-dominant (GP-NDH) hands] tests. We assessed viral effects on SIP and motor functions. HIV-infected persons had significantly lower (worse) T scores on GP-DH, WAIS-IIIDS, Stroop Word-Reading, TMT-A; lower motor and SIP summary T scores. Significantly higher proportion of cases (20.7%) than controls (10.3%) had impaired SIP. Male cases had better T scores than female cases on GP-NDH, WAIS-IIIDS, WAIS-IIISS, TMT-A, CTT1; better SIP summary T scores. Antiretroviral therapy (ART) was associated with significantly better T scores on GP-NDH, WAIS-IIIDS, Stroop Color-Naming; better motor and SIP summary T scores. Cases with higher CD4 had better T scores on WAIS-IIIDS, TMT-A, CTT1; better SIP summary T scores. Overall, we demonstrate that HIV infection in Cameroon is associated with deficits in SIP and motor functions; ART and higher CD4 are associated with better cognitive performance. We provide SIP and psychomotor functions normative standards, which will be useful for neurobehavioral studies in Cameroon of diseases affecting the brain.

Attention/Working Memory, Learning and Memory in Adult Cameroonians: Normative Data, Effects of HIV Infection and Viral Genotype

OBJECTIVE

There is lack of Cameroonian adult neuropsychological (NP) norms, limited knowledge concerning HIV-associated neurocognitive disorders in Sub-Saharan Africa, and evidence of differential inflammation and disease progression based on viral subtypes. In this study, we developed demographically corrected norms and assessed HIV and viral genotypes effects on attention/working memory (WM), learning, and memory.

METHOD

We administered two tests of attention/WM [Paced Auditory Serial Addition Test (PASAT)-50, Wechsler Memory Scale (WMS)-III Spatial Span] and two tests of learning and memory [Brief Visuospatial Memory Test-Revised (BVMT-R), Hopkins Verbal Learning Test-Revised (HVLT-R)] to 347 HIV+ and 395 seronegative adult Cameroonians. We assessed the effects of viral factors on neurocognitive performance.

RESULTS

Compared to controls, people living with HIV (PLWH) had significantly lower T-scores on PASAT-50 and attention/WM summary scores, on HVLT-R total learning and learning summary scores, on HVLT-R delayed recall, BVMT-R delayed recall and memory summary scores. More PLWH had impairment in attention/WM, learning, and memory. Antiretroviral therapy (ART) and current immune status had no effect on T-scores. Compared to untreated cases with detectable viremia, untreated cases with undetectable viremia had significantly lower (worse) T-scores on BVMT-R total learning, BVMT-R delayed recall, and memory composite scores. Compared to PLWH infected with other subtypes (41.83%), those infected with HIV-1 CRF02_AG (58.17%) had higher (better) attention/WM T-scores.

CONCLUSIONS

PLWH in Cameroon have impaired attention/WM, learning, and memory and those infected with CRF02_AG viruses showed reduced deficits in attention/WM. The first adult normative standards for assessing attention/WM, learning, and memory described, with equations for computing demographically adjusted T-scores, will facilitate future studies of diseases affecting cognitive function in Cameroonians.

Frequency and Predictors of HIV-Related Cognitive Impairment in East Africa: The Africa Cohort Study (AFRICOS)

BACKGROUND

Medication adherence is a critical issue in achieving viral suppression targets, particularly in resource-limited countries. As HIV-related cognitive impairment (CI) impacts adherence, we examined frequency and predictors of CI in the African Cohort Study.

SETTING

Cross-sectional examination of enrollment data from President's Emergency Plan for AIDS Relief supported clinic sites.

METHODS

In a 30-minute cognitive assessment, CI was defined as -1SD on 2 tests or -2SD on one, as compared with 429 controls. We performed univariable and multivariable logistic and linear models examining clinical and demographic factors associated with CI and global neuropsychological performance (NP-6).

RESULTS

Two thousand four hundred seventy-two HIV+ participants from Kenya (n = 1503), Tanzania (n = 469), and Uganda (n = 500). The mean (SD) age was 39.7 (10.7) years, and 1452 (59%) were women. The majority reported completing or partially completing primary school (n = 1584, 64%). Mean (SD) current and nadir CD4 count were 463 (249) and 204 (221) cells/mm, respectively; 1689 (68%) were on combination antiretroviral therapy. Nine hundred thirty-nine (38%) HIV+ versus 113 (26%) HIV- individuals showed CI: (P < 0.001). We found significant effects of literacy [odds ratio (OR): 0.3; 95% CI: 0.2 to 0.4; P < 0.001] and World Health Organization stage 4 (OR: 1.5; 95% CI: 1.0 to 2.q; P = 0.046) on CI. Tanzanians (OR: 3.2; 95% CI: 2.4 to 4.3; P < 0.001) and Kenyans (OR: 2.0; 95% CI: 1.6 to 2.6; P < 0.001) had higher risk of CI compared with Ugandans. Results were relatively unchanged in predictive models of NP-6, with the only difference being an additional significant effect of current CD4 cell count (coeff: 0.0; 95% CI: 0.0 to 0.0; P = 0.005).

CONCLUSIONS

Literacy, country, World Health Organization stage, and current CD4 cell count were associated with increased risk of cognitive dysfunction. Our findings help optimize care practices in Africa, illustrating the importance of strategies for early and effective viral-immunological control.

Functional deficits and other psychiatric associations with abnormal scores on the Montreal Cognitive Assessment (MoCA) in older HIV-infected patients

OBJECTIVE

The authors assessed the association of physical function, social variables, functional status, and psychiatric co-morbidity with cognitive function among older HIV-infected adults.

DESIGN

From 2012-2014, a cross-sectional study was conducted among HIV-infected patients ages 50 or older who underwent comprehensive clinical geriatric assessment.

SETTING

Two San Francisco HIV clinics.

PARTICIPANTS

359 HIV-infected patients age 50 years or older.

MEASUREMENTS

Unadjusted and adjusted Poisson regression measured prevalence ratios and 95% confidence intervals for demographic, functional and psychiatric variables and their association with cognitive impairment using a Montreal Cognitive Assessment (MoCA) score < 26 as reflective of cognitive impairment.

RESULTS

Thirty-four percent of participants had a MoCA score of < 26. In unadjusted analyses, the following variables were significantly associated with an abnormal MoCA score: born female, not identifying as homosexual, non-white race, high school or less educational attainment, annual income < $10,000, tobacco use, slower gait speed, reported problems with balance, and poor social support. In subsequent adjusted analysis, the following variables were significantly associated with an abnormal MoCA score: not identifying as homosexual, non-white race, longer 4-meter walk time, and poor social support. Psychiatric symptoms of depressive, anxiety, and post-traumatic stress disorders did not correlate with abnormal MoCA scores.

CONCLUSIONS

Cognitive impairment remains common in older HIV-infected patients. Counter to expectations, co-morbid psychiatric symptoms were not associated with cognitive impairment, suggesting that cognitive impairment in this sample may be due to neurocognitive disorders, not due to other psychiatric illness. The other conditions associated with cognitive impairment in this sample may warrant separate clinical and social interventions to optimize patient outcomes.

Prevalence and Correlates of Neurocognitive Disorders among HIV Patients on Antiretroviral Therapy at a Kenyan Hospital

Background

HIV-associated neurocognitive disorders (HAND) represent a spectrum of cognitive abnormalities affecting attention, concentration, learning, memory, executive function, psychomotor speed, and/or dexterity. Our objectives in this analysis are to determine the prevalence of HAND and the covariates in a Kenyan population.

Methods

We conducted a cross-sectional study in a convenient sample of people living with HIV on antiretroviral therapy (ART) attending routine care visits at the Kenyatta National Hospital HIV clinic between July and August 2015. Baseline demographics were obtained using interviewer-administered questionnaires; clinical data were abstracted from patient records. Trained research clinicians determined the neurocognitive status by administration of the International HIV Dementia Scale (IHDS), the Montreal Cognitive Assessment (MOCA) scale, and the Lawton Instrumental Activities of Daily Living (IADL) scale. Cognitive impairment was defined as a score of ≤26 on the MOCA and ≤10 on the IHDS. Descriptive analysis and logistic regression to determine predictors of screening positive for HAND were done with the significance value set at <0.05.

Results

We enrolled 345 participants (202 men; 143 women). The mean age of the study population was 42 years (±standard deviation (SD) 9.5). Mean duration since HIV diagnosis and mean duration on ART were 6.3 (±SD 3.7) and 5.6 years (±SD 3.4), respectively. Median CD4 count at interview was 446 cells/mm³ (interquartile range (IQR) 278–596). Eighty-eight percent of participants screened positive for HAND, of whom 87% had asymptomatic neurocognitive impairment (ANI) and minor neurocognitive disorders (MND) grouped together while 1% had HIV-associated dementia (HAD). Patients on AZT/3TC/EFV were 3.7 times more likely to have HAND (OR = 3.7, p=0.03) compared to other HAART regimens. In the adjusted analysis, women were more likely to suffer any form of HAND than men (aOR = 2.17, 95% CI: 1.02, 4.71; p=0.045), whereas more years in school and a higher CD4 count (aOR = 0.58, 95% CI: 0.38, 0.88; p=0.012), (aOR = 0.998, 95% CI 0.997, 0.999; p=0.013) conferred a lowered risk.

Conclusion

Asymptomatic and mild neurocognitive impairment is prevalent among people living with HIV on treatment. Clinical care for HIV-positive patients should involve regular screening for neurocognitive disorders while prioritizing women and those with low education and/or low CD4 counts.

Neurological disorders in HIV in Africa: a review

BACKGROUND

Neurological disorders in HIV infection are a common cause of morbidity and mortality. The aim of this paper is to provide a narrative overview of up to date information concerning neurological disorders affecting HIV infected persons in Africa.

METHODS

Seminal research concerning neurological disorders among HIV-infected adults in sub-Saharan Africa from prior to 2000 was combined with an in-depth search of PubMed to identify literature published from 2000 to 2017. The following Mesh terms were used. "Nervous System Diseases" "HIV Infections" and "Africa South of the Sahara" and "Seizures" or "Spinal Cord Diseases" or "Peripheral Nervous System Diseases" or "AIDS Dementia Complex" or "Opportunistic Infections" or "Immune Reconstitution Inflammatory Syndrome" or "Stroke". Only those articles written in English were used. A total of 352 articles were identified, selected and reviewed and 180 were included in the study. These included case series, observational studies, interventional studies, guidelines and reviews with metanalyses. The author also included 15 publications on the subject covering the earlier phase of the HIV epidemic in Africa from 1987 to 1999 making a total of 195 references in the study. This was combined with extensive personal experience diagnosing and treating these neurological disorders.

RESULTS

Neurological disorders were common, typically occurring in WHO stages III/IV. These were in three main categories: those arising from opportunistic processes mostly infections, direct HIV infection and autoimmunity. The most common were those arising from direct HIV infection occurring in >50%. These included HIV-associated neurocognitive dysfunction (HAND), neuropathy and myelopathy. Opportunistic infections occurred in >20% and frequently had a 6-9-month mortality rate of 60-70%. The main causes were cryptococcus, tuberculosis, toxoplasmosis and acute bacterial meningitis. Concurrent systemic tuberculosis occurred in almost 50%.

CONCLUSION

Neurological disorders are common in HIV in Africa and the main CNS opportunistic infections result in high mortality rates. Strategies aimed at reducing their high burden, morbidity and mortality include early HIV diagnosis and anti-retroviral therapy (ART), screening and chemoprophylaxis of main opportunistic infections, improved clinical diagnosis and management and programme strengthening.

Stigma and epilepsy in onchocerciasis-endemic regions in Africa: a review and recommendations from the onchocerciasis-associated epilepsy working group

Background

In onchocerciasis-endemic areas, particularly in those with a sub-optimal onchocerciasis control programme, a high prevalence of epilepsy is observed. Both onchocerciasis and epilepsy are stigmatizing conditions. The first international workshop on onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium (12–14 October 2017) and during this meeting, an OAE alliance was established. In this paper, we review what is known about epilepsy-associated stigma in onchocerciasis-endemic regions, and present the recommendations of the OAE alliance working group on stigma.

Main body

For this scoping review, literature searches were performed on the electronic databases PubMed, Scopus and Science Direct using the search terms “epilepsy AND onchocerciasis AND stigma”. Hand searches were also undertaken using Google Scholar, and in total seven papers were identified that addressed epilepsy-related stigma in an onchocercisasis-endemic area. Due to the limited number of published research papers on epilepsy-associated stigma in onchocerciasis-endemic areas, other relevant literature that describes important aspects related to stigma is discussed. The thematic presentation of this scoping review follows key insights on the barriers to alleviating the social consequences of stigma in highly affected onchocerciasis-endemic areas, which were established by experts during the working group on stigma and discrimination at the first international workshop on OAE. These themes are: knowledge gaps, perceived disease aetiology, access to education, marriage restrictions, psycho-social well-being, burden on the care-giver and treatment seeking behaviour. Based on the literature and expert discussions during the OAE working group on stigma, this paper describes important issues regarding epilepsy-related stigma in onchocerciasis-endemic regions and recommends interventions that are needed to reduce stigma and discrimination for the improvement of the psycho-social well-being of persons with epilepsy.

Conclusions

Educating healthcare workers and communities about OAE, strengthening onchocerciasis elimination programs, decreasing the anti-epileptic treatment gap, improving the care of epilepsy-related injuries, and prioritising epilepsy research is the way forward to decreasing the stigma associated with epilepsy in onchocerciasis-endemic regions.

Electronic supplementary material

The online version of this article (10.1186/s40249-019-0544-6) contains supplementary material, which is available to authorized users.

Neurocognitive Impairment Risk Among Individuals With Multiple Drug-Resistant Tuberculosis and Human Immunodeficiency Virus Coinfection: Implications for Systematic Linkage to and Retention of Care in Tuberculosis/Human Immunodeficiency Virus Treatment

Although neurocognitive impairment (NCI) is a well-recognized challenge in human immunodeficiency virus (HIV), there is little evidence regarding it among individuals with multiple drug-resistant tuberculosis (MDR-TB) within HIV endemic sub-Saharan Africa. The extent of NCI risk, particularly HIV-associated neurocognitive disorders (HAND) risk, was investigated in 200 microbiologically confirmed inpatients with MDR-TB at a TB-specialist hospital in KwaZulu-Natal Province, South Africa. Within this population, the prevalence of HIV coinfection, major depressive episode, and substance use disorder was 89.50%, 10.50%, and 7.00%, respectively. After excluding individuals with major depressive episode/substance use disorder and monoinfection (i.e., MDR-TB without HIV), the prevalence of HAND risk was 43.5%. Older and low-income individuals had significantly greater odds of HAND risk, whereas those with family members/relatives who work(ed) in the health services had lower odds. The role of timely linkage to and retention of care in TB/HIV treatment to offset cognitive decline in MDR-TB/HIV coinfected individuals needs to be investigated further.

Prevalence of Cognitive Impairment and Its Predictors among HIV/AIDS Patients on Antiretroviral Therapy in Jimma University Medical Center, Southwest Ethiopia

Background

Cognitive impairment among human immunodeficiency virus (HIV) infected patients can lead to treatment nonadherence, faster progression of the illness, disability, and bed ridden state if we fail to detect it early. However, there is scarcity of previous published studies in Ethiopia on the assessment of cognitive impairment among HIV-positive patients. Hence, this study aimed to determine the prevalence and associated factors of cognitive impairment among HIV-positive patients receiving antiretroviral therapy (ART) at Jimma University Medical Center, Ethiopia.

Methods

Hospital-based cross-sectional study was conducted among 328 HIV-positive patients attending Jimma University Medical Center, Ethiopia. Data were collected from a face-to-face interview and review of medical records using semistructured questionnaire. Validated International HIV Dementia Scale (IHDS) was used to screen for cognitive impairment. Data was analyzed using SPSS version 20.

Results

A total of 328 (191 females and 137 males) HIV-positive patients were included in the study with a response rate of 97.04%. The prevalence of cognitive impairment among HIV-positive patients was 35.7%. Factors significantly associated with cognitive impairment were age group of 41-64 years (adjusted odds ratio [AOR] = 3.1, 95% confidence interval [CI] (1.3, 7.4)], plasma HIV-1 RNA load between 1.7log10 and 3log10 copies/ml [AOR = 2.2, 95% CI (1.1,4.3)] and ≥ 3log10 copies/ml [AOR = 7.5, 95% CI (2.6, 21.5)], khat chewing [AOR = 4.4, 95% CI (2.3, 8.3)], and clinical stage III of the disease [AOR = 5.6, 95% CI (1.7, 19.2)].

Conclusion

Despite the use of ART, the burden of cognitive impairment among HIV patients was high. Older age, khat chewing, advanced stage of the disease, and higher viral load were the independent factors associated with cognitive impairment. Thus, continuous screening of cognitive impairment, identification of the possible risk factors, and proper management strategy should be designed.

The alpha7-nicotinic receptor contributes to gp120-induced neurotoxicity: implications in HIV-associated neurocognitive disorders

Currently, there are no specific therapies to treat HIV-1 associated neurocognitive disorders (HAND). The HIV-1 envelope, gp120, induces neuropathological changes similar to those in HAND patients; furthermore, it triggers an upregulation of the α7-nicotinic acetylcholine receptor (α7-nAChR), facilitating intracellular calcium overload and neuronal cell death. Using a gp120_IIIB-transgenic mouse (gp120-tgm) model, we demonstrate that α7-nAChRs are upregulated on striatal neurons. Activation of α7-nAChRs leads to an increase in both intracellular calcium and percentage of apoptotic cells, which can be abrogated by antagonizing the receptor, suggesting a role for α7-nAChRs in gp120-induced neurotoxicity. Moreover, we demonstrate for the first time that gp120-tgm have learning deficiencies on a striatum-dependent behavioral task. They also show locomotor deficiencies, which improved with α7-nAChR antagonists, further supporting a role for this receptor in gp120-induced neurotoxicity. Together, these results uncover a new mechanism through which gp120-induced modulation of α7-nAChRs in the striatum can contribute to HAND development.

Notes on the Recent History of Neuroscience in Africa

Neuroscience began with neuroanatomy and neurosurgery in Egypt more than 5000 years ago. Knowledge grew over time and specialized neurosurgery centers were established in north Africa in the eleventh century. However, it was not until the twentieth century that neuroscience research became established in sub-Saharan Africa. In most African countries, clinical research focused on understanding the rationale and improving treatment of epilepsy, infections, nutritional neuropathies, stroke and tumors. Significant advances were made. In the twenty-first century, African knowledge expanded to include all branches of neuroscience, contributing to genetic, biochemical and inflammatory determinants of brain disorders. A major focus of basic neuroscience research has been, and is, investigation of plant extracts, drugs and stress in animal models, providing insight and identifying potential novel therapies. A significant event in the history of African neuroscience was the founding of the Society of Neuroscientists of Africa (SONA) in 1993. The International Brain Research Organization (IBRO) supported SONA conferences, as well as workshops and neuroscience training schools in Africa. Thanks to their investment, as well as that of funding agencies, such as the National Institutes of Health (NIH), International Society for Neurochemistry (ISN), World Federation of Neurosurgical Societies (WFNS), World Federation of Neurology (WFN) and the International League Against Epilepsy (ILAE), neuroscience research is well-established in Africa today. However, in order to continue to develop, African neuroscience needs continued international support and African neuroscientists need to engage in policy and decision-making to persuade governments to fund studies that address the unique regional needs in Africa.

Prevalence of HIV Associated Neurocognitive Deficit among HIV Positive People in Ethiopia: A Cross Sectional Study at Ayder Referral Hospital

BACKGROUND

HIV associated neurocognitive deficit impairs motor activity, neuropsychiatric functioning, daily activity and work activity usually due to the immune suppression effect of the virus. Sub-Saharan region including Ethiopia is the region with the highest burden of HIV. However, a few studies are found on this aspect nationally. This study was aimed at determining the prevalence and the factors associated with cognitive impairment among HIV positive people in Ethiopia who attended Ayder Comprehensive Specialized Hospital.

METHOD

A hospital based cross sectional study was employed on 234 participants selected using systematic random sampling technique. Data was collected thrpugh face-to-face interview, observation and document review. International HIV dementia scale, activity of daily living scale and Hospital Anxiety and Depression scale were used to assess neuro cognitive deficit, activity of daily living, anxiety and depression respectively. The data was analyzed by using SPSS window 20.

RESULTS

About 88% of the subjects were receiving highly active antiretroviral therapy. The magnitude of Neuro cognitive deficit was 33.3% (95% CI; 27.7% - 40.6%). Impairment in the activity of daily living was observed on 9.8% of the participants. Besides, 55.6% and 67.1% had anxiety and depressive disorders respectively. Late clinical stage of the illness (AOR= 4.2 (95% CI; 1.19, 14.44)) and impairment in the activity of daily living were significantly associated with neurocognitive deficit (AOR= 7.19 (95% CI; 1.73, 21.83).

CONCLUSION

A higher prevalence of neurocognitive deficit was observed that was related to impaired activity of daily living and being in late stages of the illness. Hence, this should be a strong alarm for early detection of the problem and consistent review of the treatment regimen.

Neurocognitive Function at the First-Line Failure and on the Second-Line Antiretroviral Therapy in Africa: Analyses From the EARNEST Trial

OBJECTIVE

To assess neurocognitive function at the first-line antiretroviral therapy failure and change on the second-line therapy.

DESIGN

Randomized controlled trial was conducted in 5 sub-Saharan African countries.

METHODS

Patients failing the first-line therapy according to WHO criteria after >12 months on non-nucleoside reverse transcriptase inhibitors-based regimens were randomized to the second-line therapy (open-label) with lopinavir/ritonavir (400 mg/100 mg twice daily) plus either 2-3 clinician-selected nucleoside reverse transcriptase inhibitors, raltegravir, or as monotherapy after 12-week induction with raltegravir. Neurocognitive function was tested at baseline, weeks 48 and 96 using color trails tests 1 and 2, and the Grooved Pegboard test. Test results were converted to an average of the 3 individual test z-scores.

RESULTS

A total of 1036 patients (90% of those >18 years enrolled at 13 evaluable sites) had valid baseline tests (58% women, median: 38 years, viral load: 65,000 copies per milliliter, CD4 count: 73 cells per cubic millimeter). Mean (SD) baseline z-score was -2.96 (1.74); lower baseline z-scores were independently associated with older age, lower body weight, higher viral load, lower hemoglobin, less education, fewer weekly working hours, previous central nervous system disease, and taking fluconazole (P < 0.05 in multivariable model). Z-score was increased by mean (SE) of +1.23 (0.04) after 96 weeks on the second-line therapy (P < 0.001; n = 915 evaluable), with no evidence of difference between the treatment arms (P = 0.35).

CONCLUSIONS

Patients in sub-Saharan Africa failing the first-line therapy had low neurocognitive function test scores, but performance improved on the second-line therapy. Regimens with more central nervous system-penetrating drugs did not enhance neurocognitive recovery indicating this need not be a primary consideration in choosing a second-line regimen.

Prevalence and Correlates of HIV-Associated Neurocognitive Disorders (HAND) in Northwestern Nigeria

HIV-associated Neurocognitive Disorders (HAND) are common among HIV-positive individuals. This study explored the prevalence and correlates of HAND in Nigeria. 80 HIV-positive and 40 HIV-negative adults selected from Aminu Kano Teaching Hospital (AKTH) received comprehensive evaluations. A multidomain neuropsychological test (MDNPT) battery assessing 7 domains was administered to the participants and their performance was combined with measures of functional status to classify impairments into various grades of HAND. Univariate and multivariate analyses were performed to identify correlates of symptomatic HAND. Among the HIV-positive individuals, 50% were highly active antiretroviral therapy-experienced (HAART+) and 50% were highly active antiretroviral therapy naive (HAART−). Symptomatic HAND was found among 40% of the HAART− individuals and 30% of the HAART+ individuals. Respective prevalence of HIV-associated dementia (HAD) was 23% and 5%, respectively (p = 0.0002). In a binary logistic regression model, only fewer years of education independently predicted symptomatic HAND [Odds Ratio (OR) = 1.2, 95% confidence interval (CI) = 1.04–1.44, p = 0.016]. The prevalence of HAND in Nigeria is high with HAD being commoner among HAART− patients. Provision of HAART and strict monitoring of patients at risk of HAND are needed to scale down the burden of the disease.

Paving the path to HIV neurotherapy: Predicting SIV CNS disease

HIV-induced damage to the CNS remains a major challenge for over 30 million people in the world despite the successes of combined antiretroviral therapy in limiting viral replication. Predicting development and progression of HIV-associated CNS disease is crucial because prevention and early intervention could be more effective than attempts to promote repair. The SIV/macaque model is the premier platform to study HIV neuropathogenesis, including discovery of predictive factors such as neuroprotective host genes and both blood and CSF biomarkers that precede and predict development of SIV CNS disease. This report details the role of macaque MHC class I genes, longitudinal alterations in biomarkers in the circulation, and expression of inflammatory and neuronal damage markers in CSF using samples from SIV-inoculated pigtailed macaques collected during acute, asymptomatic, and terminal stages of infection.

The relationship between HIV and prevalence of disabilities in sub-Saharan Africa: systematic review (FA)

OBJECTIVE

To systematically review evidence on the prevalence and risk of disabilities among children and adults living with HIV in sub-Saharan Africa.

METHODS

Articles were identified from 1980 to June 2013 through searching seven electronic databases. Epidemiological studies conducted in sub-Saharan Africa that explored the association between HIV status and general disability or specific impairments, with or without an HIV-uninfected comparison group, were eligible for inclusion.

RESULTS

Of 12 867 records initially identified, 61 papers were deemed eligible for inclusion. The prevalence of disability was high across age groups, impairment types and study locations. Furthermore, 73% of studies using an HIV- comparator found significantly lower levels of functioning in people living with HIV (PLHIV). By disability type, the results were as follows: (i) for studies measuring physical impairments (n = 14), median prevalence of limitations in mobility and motor function among PLHIV was 25.0% (95% CI: 21.8-28.2%). Five of eight comparator studies found significantly reduced functioning among PLHIV; for arthritis, two of three studies which used an HIV- comparison group found significantly increased prevalence among PLHIV; (ii) for sensory impairment studies (n = 17), median prevalence of visual impairment was 11.2% (95%CI: 9.5-13.1%) and hearing impairment was 24.1% (95%CI: 19.2-29.0%) in PLHIV. Significantly increased prevalence among PLHIV was found in one of four (vision) and three of three studies (hearing) with comparators; (iii) for cognitive impairment in adults (n = 30), median prevalence for dementia was 25.3% (95% CI: 22.0-28.6%) and 40.9% (95% CI: 37.7-44.1%) for general cognitive impairment. Across all types of cognitive impairment, twelve of fourteen studies found a significant detrimental effect of HIV infection; (iv) for developmental delay in children with HIV (n = 20), median prevalence of motor delay was 67.7% (95% CI: 62.2-73.2%). All nine studies that included a comparator found a significant difference between PLHIV and controls; for cognitive development and global delay, a significant detrimental effect of HIV was found in five of six and one of two studies, respectively. In the nine cohort studies comparing vertically infected and uninfected children, eight showed a significant gap in development over time in children with HIV. Finally, fifteen of thirty-one (48%) studies found a statistically significant dose-response relationship between indicators of disease progression (CD4 or WHO stage) and disability.

CONCLUSIONS

HIV is widespread in sub-Saharan Africa and the evidence suggests that it is linked to disabilities, affecting a range of body structures and functions. More research is needed to better understand the implications of HIV-related disability for individuals, their families as well as those working in the fields of disability and HIV so that appropriate interventions can be developed.

Association of HIV and ART with cardiometabolic traits in sub-Saharan Africa: a systematic review and meta-analysis

Background Sub-Saharan Africa (SSA) has the highest burden of HIV in the world and a rising prevalence of cardiometabolic disease; however, the interrelationship between HIV, antiretroviral therapy (ART) and cardiometabolic traits is not well described in SSA populations.

Methods We conducted a systematic review and meta-analysis through MEDLINE and EMBASE (up to January 2012), as well as direct author contact. Eligible studies provided summary or individual-level data on one or more of the following traits in HIV+ and HIV-, or ART+ and ART- subgroups in SSA: body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TGs) and fasting blood glucose (FBG) or glycated hemoglobin (HbA1c). Information was synthesized under a random-effects model and the primary outcomes were the standardized mean differences (SMD) of the specified traits between subgroups of participants.

Results Data were obtained from 49 published and 3 unpublished studies which reported on 29 755 individuals. HIV infection was associated with higher TGs [SMD, 0.26; 95% confidence interval (CI), 0.08 to 0.44] and lower HDL (SMD, −0.59; 95% CI, −0.86 to −0.31), BMI (SMD, −0.32; 95% CI, −0.45 to −0.18), SBP (SMD, −0.40; 95% CI, −0.55 to −0.25) and DBP (SMD, −0.34; 95% CI, −0.51 to −0.17). Among HIV+ individuals, ART use was associated with higher LDL (SMD, 0.43; 95% CI, 0.14 to 0.72) and HDL (SMD, 0.39; 95% CI, 0.11 to 0.66), and lower HbA1c (SMD, −0.34; 95% CI, −0.62 to −0.06). Fully adjusted estimates from analyses of individual participant data were consistent with meta-analysis of summary estimates for most traits.

Conclusions Broadly consistent with results from populations of European descent, these results suggest differences in cardiometabolic traits between HIV-infected and uninfected individuals in SSA, which might be modified by ART use. In a region with the highest burden of HIV, it will be important to clarify these findings to reliably assess the need for monitoring and managing cardiometabolic risk in HIV-infected populations in SSA.

Epidemiology of neurodegenerative diseases in sub-Saharan Africa: a systematic review

BACKGROUND

Sub-Saharan African (SSA) countries are experiencing rapid transitions with increased life expectancy. As a result the burden of age-related conditions such as neurodegenerative diseases might be increasing. We conducted a systematic review of published studies on common neurodegenerative diseases, and HIV-related neurocognitive impairment in SSA, in order to identify research gaps and inform prevention and control solutions.

METHODS

We searched MEDLINE via PubMed, 'Banque de Données de Santé Publique' and the database of the 'Institut d'Epidemiologie Neurologique et de Neurologie Tropicale' from inception to February 2013 for published original studies from SSA on neurodegenerative diseases and HIV-related neurocognitive impairment. Screening and data extraction were conducted by two investigators. Bibliographies and citations of eligible studies were investigated.

RESULTS

In all 144 publications reporting on dementia (n = 49 publications, mainly Alzheimer disease), Parkinsonism (PD, n = 20), HIV-related neurocognitive impairment (n = 47), Huntington disease (HD, n = 19), amyotrophic lateral sclerosis (ALS, n = 15), cerebellar degeneration (n = 4) and Lewy body dementia (n = 1). Of these studies, largely based on prevalent cases from retrospective data on urban populations, half originated from Nigeria and South Africa. The prevalence of dementia (Alzheimer disease) varied between <1% and 10.1% (0.7% and 5.6%) in population-based studies and from <1% to 47.8% in hospital-based studies. Incidence of dementia (Alzheimer disease) ranged from 8.7 to 21.8/1000/year (9.5 to 11.1), and major risk factors were advanced age and female sex. HIV-related neurocognitive impairment's prevalence (all from hospital-based studies) ranged from <1% to 80%. Population-based prevalence of PD and ALS varied from 10 to 235/100,000, and from 5 to 15/100,000 respectively while that for Huntington disease was 3.5/100,000. Equivalent figures for hospital based studies were the following: PD (0.41 to 7.2%), ALS (0.2 to 8.0/1000), and HD (0.2/100,000 to 46.0/100,000).

CONCLUSIONS

The body of literature on neurodegenerative disorders in SSA is large with regard to dementia and HIV-related neurocognitive disorders but limited for other neurodegenerative disorders. Shortcomings include few population-based studies, heterogeneous diagnostic criteria and uneven representation of countries on the continent. There are important knowledge gaps that need urgent action, in order to prepare the sub-continent for the anticipated local surge in neurodegenerative diseases.

Neurology and the Global HIV Epidemic

The vast majority of people living with human immunodeficiency virus (HIV) infection reside in resource-limited settings. As compared with resource-rich settings, there are important differences in the epidemiology and outcomes of HIV infection in resource-limited settings. Nonetheless, little HIV neurology research occurs in these regions. We will first review clinical, epidemiological, and translational HIV neurology research originating from resource-limited settings. We will then discuss the barriers to conducting neurologic research, such as limited human resources, diagnostics, and access to medications. Finally, we will review existing initiatives to build capacity for research in resource-limited settings. Despite the barriers, there is growing interest in and opportunities for collaborative international neurologic research. Including diverse viral and human populations from across the globe in research opens possibilities for important implementation science, clinically oriented science, and basic science discoveries.

Absence of neurocognitive impairment in a large Chinese sample of HCV-infected injection drug users receiving methadone treatment

BACKGROUND

Prior research has demonstrated neuropsychological (NP) impairment in persons with histories of injection drug use (IDU), hepatitis C virus (HCV) infection, and methadone maintenance treatment (MMT), individually, but little is known about the NP effects of these three risk factors in combination. This issue is particularly important in China, which is addressing its highly HCV-comorbid IDU epidemic with widespread government sponsored MMT, especially in light of recent evidence suggesting that methadone may be neuroprotective in some circumstances.

METHODS

We administered a comprehensive NP test battery to 195 Chinese heroin IDU individuals taking MMT (IDU+ group), the majority of whom were also HCV+ (87%; n=169), and compared their NP performance to that of 198 demographically comparable, non-IDU Chinese controls (IDU- group). All participants in both groups tested negative for HIV infection, which is also a common comorbidity in the Chinese IDU population.

RESULTS

The IDU+ group did not have an increased rate of global NP impairment, or perform significantly worse on any individual NP test measure. Within the IDU+ group, liver disease characteristics and reported details of heroin use were not significantly associated with NP performance.

CONCLUSION

Failure to detect NP impairment in IDU+ subjects with or without HCV infection was surprising, particularly considering the previously demonstrated sensitivity of our NP battery to neurocognitive disorders associated with HIV infection in China. One possible explanation, which should be explored in future research, is the potential neuroprotective effect of methadone in the context of HCV infection and/or heroin withdrawal.

HIV-associated neurocognitive disorder in HIV-infected Koreans: the Korean NeuroAIDS Project

OBJECTIVES

HIV-associated neurocognitive disorder (HAND) is an independent predictor of early mortality and is associated with many difficulties in activities of daily living. We sought to determine the prevalence of and risk factors for HAND in HIV-infected Koreans. In addition, we investigated the performance of screening tools and components of neuropsychological (NP) tests for diagnosing HAND.

METHODS

HIV-infected patients were enrolled consecutively from two different urban teaching hospitals in Seoul, South Korea between March 2012 and September 2012. Participants completed a detailed NP assessment of six cognitive domains commonly affected by HIV. The Frascati criteria were used for diagnosing HAND. Four key questions, the International HIV Dementia Scale (IHDS) and Montreal Cognitive Assessment (MoCA)-K were also assessed as potential tools for screening for HAND.

RESULTS

Among the 194 participants, the prevalence of HAND was 26.3%. Asymptomatic neurocognitive impairment and minor neurocognitive disorder accounted for 52.9 and 47.1% of the patients with HAND, respectively. In multivariate analysis, haemoglobin (Hb) level ≤ 13 g/dL (P = 0.046) and current use of a protease inhibitor-based regimen (P = 0.031) were independent risk factors for HAND. The sensitivity and specificity of the IHDS were 72.6 and 60.8%, and those of MoCA-K were 52.9 and 73.4%, respectively. The IHDS (P < 0.001) and MoCA-K (P < 0.001) were both useful for screening for HAND. Among NP tests, the sensitivity and specificity of the Grooved Pegboard Test were 90.2 and 72.0%, and those of the Wisconsin Card Sorting Test were 61.2 and 84.4%, respectively.

CONCLUSIONS

HAND is a prevalent comorbidity in HIV-infected Koreans. Active screening and diagnosis with effective tools, such as the IHDS, MoCA-K and Grooved Pegboard Test, could be used to identify this important complication.

Identifying risk factors for HIV-associated neurocognitive disorders using the international HIV dementia scale

HIV-associated neurocognitive disorders (HAND) persist despite great advancements in combination antiretroviral therapy (cART). The gold standard for diagnosing cognitive impairment consists of a time-consuming neuropsychological battery of tests given by a trained neuropsychologist, however in the outpatient HIV clinic this is not feasible. The International HIV Dementia Scale (IHDS) was developed to help identify individuals with cognitive impairment in the outpatient setting. The IHDS is moderately sensitive for detecting more symptomatic forms of HAND but sensitivity has been shown to be poor in mild impairment. The IHDS has not been evaluated in developed countries in large cohort populations. We conducted a prospective cross-sectional study of only HIV+ individuals in an urban clinic and evaluated the prevalence of HAND and associated risk factors for cognitive impairment using the IHDS. A total of 507 HIV+ individuals participated in the study of which the majority were male (65 %) and African American (68 %); and 41 % had cognitive impairment. On multivariate analysis, African American race (p = 2.21), older age (p = 1.03), high school education or less (p = 2.03) and depression (p = 1.05) were associated with cognitive impairment. The high prevalence of HAND in this group suggests that more severe forms of HAND persist despite cART. Identified risk factors were non-HIV-related and suggest that environmental and sociodemographic factors have a significant impact on cognitive functioning and should be given more attention. The IHDS should be further evaluated in large cohort HIV+ and HIV- populations in the United States, as there remains a significant need to identify an effective brief screening tool for cognitive impairment.

Neurocognitive impairment in HIV-1-infected adults in Sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVE

To estimate the burden of HIV neurocognitive impairment (NCI) among adult patients on and off antiretroviral therapy (ART) in Sub-Saharan Africa.

METHODS

Estimates were derived from a random effects meta-analysis of prospective studies reporting HIV status, utilization of ART, and the presence of NCI determined using the International HIV Dementia Scale.

RESULTS

Sixteen studies with quality data from seven countries in Sub-Saharan Africa up to June 2012 were included. Among HIV patients, the frequency of NCI pre-ART was 42.37% (95% confidence interval (CI) 32.18-52.56%), and among those on ART for ≥6 months was 30.39% (95% CI 13.17-47.61%). Respective NCI estimates in studies from Uganda were 46.49% (95% CI 30.62-62.37%) and 28.50% (95% CI -1.31-58.30%). NCI was more common among patients with a concomitant psychiatric ailment. HIV-positive patients compared to HIV-negative controls were predisposed to NCI (odds ratio (OR) 6.49, 95% CI 1.68-25.08); the estimated unadjusted attributable risk of HIV infection leading to NCI was 85%. Meta-regression showed no associations between age, gender, CD4 cell counts, or years of education with NCI. Patients on ART were less likely to have NCI compared to HIV-infected pre-ART patients, with OR 0.36 (95% CI 0.19-0.69). In longitudinal studies with the same patients followed before and at ≥6 months after ART, the OR of NCI after ART compared to pre-ART was 0.23 (95% CI 0.14-0.37). The combined burden of NCI among pre-ART and on-ART patients in Sub-Saharan Africa was estimated at 8,121,910 (95% CI 5,772,140-10,471,680). No publication bias was observed, although residual confounding from differing environmental factors, stages of HIV infection, and viral clades might be a limitation.

CONCLUSIONS

HIV strongly predisposes to NCI leading to a huge burden in Sub-Saharan Africa, and scale-up of ART can substantially reduce it.

Prevalence, characteristics and correlates of a positive-dementia screen in patients on antiretroviral therapy in Bamenda, Cameroon: a cross-sectional study

Background

In this study we assess the prevalence, characteristics as well as socio-demographic and clinical correlates of a positive screen for HIV-associated dementia in a group of patients on antiretroviral therapy (ART) in Bamenda, Cameroon.

Methods

In a cross-sectional study, a structured questionnaire was used to collect data on 400 patients attending the Bamenda Regional Hospital AIDS-treatment Centre. Patients were assessed for neurocognitive function using the International HIV Dementia Scale (IHDS) to assess finger-tapping (FT), alternating hand sequence (AHS) and a 4-word recall (4WR), each scored on a maximum of four.

Results

A total of 297 (74%) participants were females. The total IHDS score ranged from 6–12 with a mean of 9.02 and 85% of subjects screened positive for dementia (≤10 on IHDS). Participants performed worst in the AHS assessment with a mean of 2.25 (IQR: 2–3). In multivariable analyses, screening positive for dementia was significantly associated with having primary education or less (aOR: 8.33, 95%CI: 3.85, 16.67), and having HIV symptoms (aOR: 12.16, 95%CI: 3.08, 48.05).

Conclusions

A very high proportion of patients on ART screened positive for dementia using the IHDS. This could potentially be an indication of a high prevalence of HIV-associated neurocognitive disorders in this population and or a poor performance of the IHDS in patients on ART. Future studies will need to assess the validity of the IHDS in this population of patients on ART and also evaluate long term outcomes in patients with positive dementia screens.

Depressive symptoms and neurocognitive performance among HIV-infected women

The aims of this article were to explore the relationship between depressive symptoms and neuropsychological performance in a sample of HIV-infected women, and to examine the contribution of demographic, HIV-related variables, and depressive symptoms to neurocognitive performance. In this cross-sectional study, a sample of 103 HIV-infected women, recruited from February to December 2010, were assessed for depressive symptoms (with the Beck Depression Inventory) and neurocognitive performance (with the HIV Dementia Scale). Severe depressive symptoms were reported by 31.1% of the women. Findings indicated that severe levels of depressive symptoms were significantly associated with reduced cognitive functioning in HIV-infected women, particularly in domains of attention, psychomotor speed, and construction. Older age and low education level were significantly associated with neurocognitive impairment in univariate analyses. In the multivariate model, only depressive symptoms were significantly related to neurocognitive impairment. Compared to participants with none/minimal depressive symptoms, those with moderate and severe depressive symptoms had odds ratios for neurocognitive impairment of 5.03 (95% CI, 1.33-18.99) and 3.22 (95% CI, 1.15-9.06), respectively. These findings support continued investigation of the presence of neurocognitive impairment, particularly among women, and may help mental health providers with early detection, planning, and implementation of more effective interventions. The current study was supported by Abbott Laboratories, Portugal.

Antiretroviral therapy in Indian setting: when & what to start with, when & what to switch to?

With the rapid scale up of antiretroviral therapy, there is a dramatic decline in HIV related morbidity and mortality in both developed and developing countries. Several new safe antiretroviral, and newer class of drugs and monitoring assays are developed recently. As a result the treatment guideline for the management of HIV disease continue to change. This review focuses on evolving science on Indian policy - antiretroviral therapy initiation, which drugs to start with, when to change the initial regimen and what to change.

Clinical features and preliminary studies of virological correlates of neurocognitive impairment among HIV-infected individuals in Nigeria

In Nigeria, the incidence and prevalence of human immunodeficiency virus (HIV)-related neurocognitive impairment (NCI) are unknown and there currently exists little information related to the viral correlates rates of NCI. Therefore, studies were performed to examine the potential utility of applying an established neuropsychological (NP) screening battery and detailed NP testing to detect NCI and correlations with functional impairment and the presence of specific viral signatures among infected subjects. A total of 60 HIV-1 seropositive antiretroviral-naive individuals and 56 seronegative control subjects were administered the International HIV Dementia Scale (IHDS) and assessed for functional impairment using the Karnofsky performance status scale. Fifteen HIV-infected patients and 11 controls were also administered a detailed NP battery. Blood samples from eight infected subjects, three with evidence of NCI, were obtained for molecular analysis of HIV-1 strain. Unadjusted scores on the IHDS showed that, using a recommended total score cutoff of 10, 28.8% of the HIV-1 seropositive and 16.0% of seropositive individuals scored abnormally. Results from testing using the full NP battery showed that, overall, the HIV seropositive group performed worse than the seronegative group, with effect sizes spanning from small (0.25 on the trail making test A) to large (0.82 on action fluency), and an average effect size across the battery of 0.45, which approaches that which has been recorded in other international settings. Sequencing of partial pol amplicons from viral isolates revealed that two of three patients with NCI were infected with subtype G virus and 1 with the circulating recombinant form (CRF)02_AG; all four individuals without NCI were infected with CRF_02AG. These studies demonstrate the utility of the IHDS in identifying cognitive impairment among HIV infected individuals in Nigeria. Future studies aimed at examining the burden of NCI among the population of individuals with HIV-1 infection in Nigeria and which assess the virologic correlates will contribute to the evolving understanding of the pathogenetic factors that underlie this disorder.

HIV-associated neurocognitive disorders (HAND) in a South Asian population - contextual application of the 2007 criteria

OBJECTIVES

To estimate the prevalence of HIV-associated neurocognitive disorders (HAND) among HIV patients in a multiethnic South Asian population, describe the pattern of neurocognitive impairment in HAND and the factors associated with HAND.

DESIGN

A cross-sectional survey of HIV-positive outpatients and inpatients.

SETTING

The sole referral centre for HIV/AIDS treatment in Singapore.

PARTICIPANTS

Inclusion criteria were HIV positive, age between 21 and 80 years old and at least 3 years of education. Exclusion criteria included concomitant delirium, serious systemic disease or major psychiatric illness. 265 patients did not meet criteria or declined to participate. The final sample size was 132.

OUTCOME MEASURES

The primary outcome measure was cognitive impairment based on performance on the Montreal Cognitive Assessment, International HIV Dementia Scale and Instrumental Activities of Daily Living. The secondary outcome measure was the classification of impairment based on the 2007 updated research nosology for HAND.

RESULTS

The prevalence of HAND was 22.7% of which 70% (15.9% of total) were asymptomatic neurocognitive impairment, 23.3% (5.3% of total) were mild neurocognitive disorder and 6.7% (1.5% of total) were HIV-associated dementia. Increasing age (OR 1.104, 95% CI 1.054 to 1.155, p<0.001), less education (OR 0.78, 95% CI 0.69 to 0.89, p<0.001) and low baseline CD4 count (OR 0.15, 95% CI 0.03 to 0.74, p=0.019) were associated with HAND. Delayed recall, language and abstract thinking were the domains most commonly affected, but impairment in visuospatial ability (RC 3.013, 95% CI 1.954 to 4.073, p<0.001) and attention (RC 2.205, 95% CI 1.043 to 3.367, p<0.001) were most strongly associated with HAND.

CONCLUSION

HAND is common among HIV patients in a South Asian sample, most of whom are asymptomatic. Older patients with less education and severe illness at diagnosis are at highest risk of HAND. Delayed recall is most commonly affected, but visuospatial dysfunction is most strongly associated with prevalent HAND.

Up-regulation of the neuronal nicotinic receptor α7 by HIV glycoprotein 120: potential implications for HIV-associated neurocognitive disorder

Approximately 30-50% of the >30 million HIV-infected subjects develop neurological complications ranging from mild symptoms to dementia. HIV does not infect neurons, and the molecular mechanisms behind HIV-associated neurocognitive decline are not understood. There are several hypotheses to explain the development of dementia in HIV(+) individuals, including neuroinflammation mediated by infected microglia and neuronal toxicity by HIV proteins. A key protein associated with the neurological complications of HIV, gp120, forms part of the viral envelope and can be found in the CSF of infected individuals. HIV-1-gp120 interacts with several receptors including CD4, CCR5, CXCR4, and nicotinic acetylcholine receptors (nAChRs). However, the role of nAChRs in HIV-associated neurocognitive disorder has not been investigated. We studied the effects of gp120(IIIB) on the expression and function of the nicotinic receptor α7 (α7-nAChR). Our results show that gp120, through activation of the CXCR4 chemokine receptor, induces a functional up-regulation of α7-nAChRs. Because α7-nAChRs have a high permeability to Ca(2+), we performed TUNEL staining to investigate the effects of receptor up-regulation on cell viability. Our data revealed an increase in cell death, which was blocked by the selective antagonist α-bungarotoxin. The in vitro data are supported by RT-PCR and Western blot analysis, confirming a remarkable up-regulation of the α7-nAChR in gp120-transgenic mice brains. Specifically, α7-nAChR up-regulation is observed in mouse striatum, a region severely affected in HIV(+) patients. In summary, CXCR4 activation induces up-regulation of α7-nAChR, causing cell death, suggesting that α7-nAChR is a previously unrecognized contributor to the neurotoxicity associated with HIV infection.

HIV-1 effects on neuropsychological performance in a resource-limited country, Zambia

Zambia has substantially been affected by the HIV/AIDS epidemic with prevalence rates at 14% in a population estimated at 12 million. Yet, the extent of HIV-associated neurocognitive disorders (HAND) in this population remains to be clearly understood. A series of culturally appropriate neuropsychological (NP) assessments [International HIV Dementia Scale (IHDS), Color Trails Test 1 and 2, Grooved pegboard Test, and Time Gait Test] were used to test the effects of HIV on NP performance of HIV seropositive and seronegative individuals. Twenty-two percent HIV positive individuals ARV naïve met the criteria for IHDS-defined NP impairment. Gender significantly influenced the performance on NP tests with females performing more poorly compared to males. Larger studies that will accommodate gender differences and age are necessary to generate appropriate norms in Zambia in order to better assess the prevalence of HAND in the developing country setting.

Effects of different antiretroviral agents on cerebral function in HIV-infected individuals

Since the advent of effective antiretroviral therapy, the incidence of severe HIV-associated brain disease has declined dramatically; however, more subtle forms of cerebral impairment, known as HIV-associated neurocognitive disorders, are becoming increasingly recognized. Some of the risk factors for this impairment are well described and include nadir CD4+ cell count. However, the effects of different antiretroviral agents on cerebral function are only beginning to be unraveled. Overall, there are clear beneficial effects on neurocognitive function from antiretroviral therapy. Recent data suggest that some antiretroviral agents have more potent effects on improving cerebral function, whereas other antiretroviral agents may even be associated with direct cerebral toxicities.

High prevalence of suspected HIV-associated dementia in adult Malawian HIV patients

HIV-associated dementia (HAD) has received little attention in sub-Saharan Africa, and there are no data available from Malawi. We used the International HIV Dementia Scale (IHDS), a cross-cultural, simple and validated screening tool to study the prevalence of suspected HAD, defined as an IHDS score <or=10, in adult patients of a large urban antiretroviral (ART) clinic in Blantyre, Malawi. Use of the IHDS was feasible in our setting. The overall prevalence of suspected HAD was 14.0% (95% confidence interval 8.9-19.1%); there was no significant difference in prevalence between 134 patients on ART for at least six months and 45 patients not on ART (13.4% versus 15.6%; P = 0.722). Male gender and low education level were independent risk factors of suspected HAD. More knowledge of the value of the IHDS to predict ART outcomes is required.

HIV-associated neurocognitive disorders in sub-Saharan Africa: a pilot study in Cameroon

BACKGROUND

The disease burden of human immunodeficiency virus (HIV)--acquired immunodeficiency syndrome (AIDS) is highest in sub-Saharan Africa but there are few studies on the associated neurocognitive disorders in this region. The objectives of this study were to determine whether Western neuropsychological (NP) methods are appropriate for use in Cameroon, and to evaluate cognitive function in a sample of HIV-infected adults.

METHODS

We used a battery of 19 NP measures in a cross-sectional study with 44 HIV+ adults and 44 demographically matched HIV- controls, to explore the validity of these NP measures in Cameroon, and evaluate the effect of viral infection on seven cognitive ability domains.

RESULTS

In this pilot study, the global mean z-score on the NP battery showed worse overall cognition in the HIV+ individuals. Significantly lower performance was seen in the HIV+ sample on tests of executive function, speed of information processing, working memory, and psychomotor speed. HIV+ participants with AIDS performed worse than those with less advanced HIV disease.

CONCLUSIONS

Similar to findings in Western cohorts, our results in Cameroon suggest that HIV infection, particularly in advanced stages, is associated with worse performance on standardized, Western neurocognitive tests. The tests used here appear to be promising for studying NeuroAIDS in sub-Saharan Africa.